Provide middlewares.

aiogram/dispatcher/middlewares.py

@@ -0,0 +1,24 @@
+from aiogram.dispatcher import Handler
+from aiogram.dispatcher.handler import SkipHandler
+
+
+class Middleware:
+    def __init__(self, handler, filters=None):
+        self.handler: Handler = handler
+        self.configure_handler(filters)
+
+    def configure_handler(self, filters):
+        if filters is None:
+            filters = []
+        self.handler.register(self._handle_event, filters, 0)
+
+    async def handle(self, *args, **kwargs):
+        raise NotImplementedError
+
+    async def check_data(self, *args, **kwargs):
+        return True
+
+    async def _handle_event(self, *args, **kwargs):
+        if await self.check_data(*args, **kwargs):
+            await self.handle(*args, **kwargs)
+        raise SkipHandler()